The present invention relates to a remote-control system for closures, having a portable hand held transmitter which generates and radiates directed coded control signals upon actuation of a transmission key on the hand transmitter. At least one first receiver unit is tuned to receive the control signals radiated from the hand transmitter and is arranged on a motor vehicle and triggers switching effects on a remotely controllable vehicle locking device after the received control signals have been identified as acceptable. At least one second receiver unit is tuned to receive control signals radiated as a result of the actuation of the transmission key of the hand transmitter for remotely controlling a remotely controllable access control device (such as a garage door, or the like) external to the motor vehicle. This second receiver unit is arranged outside the motor vehicle and triggers switching effects on the access control device after the received control signals have been identified as acceptable. An electrical circuit is provided for preventing at least the triggering of switching effects by the second receiver unit when the control signal radiated as a result of a single actuation of the transmission key of the hand transmitter is directed simultaneously to the first and the second receiver unit, by causing the signal arriving at the second receiver unit to differ significantly from the control signal radiated as a result of the actuation of the transmission key of the hand transmitter for remotely controlling the access control device.
A remote-control system with the above features has already been described in German Patent Document DE 4,006,125 C1. In this system, the infrared hand transmitter is used outside the vehicle for the remote control of the central door locking of the vehicle via at least one first receiver fixed to the vehicle, and also inside the vehicle for the convenient remote control of an external access control device, for example an electrical garagedoor drive, via a second receiver external to the vehicle. However, inside the vehicle, the control signals of the hand transmitter are transmitted to the second receiver via a lightguide cable which terminates in an interior hand-transmitter receptacle fixed to the vehicle and in the shell of the motor vehicle. This allows providing a plurality of outer terminations of the light-guide cable branched for this purpose.
In a simple version of the known system, if desired, technical safety precautions against an unintended simultaneous response of both the vehicle locking and the drive of the external system when the two receivers receive the hand-transmitter signal simultaneously can be relinquished in favor of a remote control ability of the external access control device which is direct, that is to say also external to the vehicle. Damage to the vehicle or to the access control device, should the vehicle be parked immediately in front of an electrically drivable garage door, can be avoided if the user takes appropriate care.
However, for the system of the above-described type there are electrical means for suppressing switching effects of the second receiver when signals radiating from the hand transmitter are received simultaneously by the first and second receivers. The switching effects of control signals received by the respective receiver units and identified as suitable occur especially: on the vehicle/at the first receiver unit in the central unlocking and locking of all of the closures; and at the access control device/second receiver unit in the opening and reclosing of an outside door, barrier, etc.
According to a first embodiment, the means for suppressing are formed by a signal converter which is provided within the light-guide cable and which converts the signal of the hand transmitter into the form or coding which can be evaluated by the second receiver unit. According to a second embodiment of the known system, an independent transmitter can be installed in the vehicle itself, and this can be activated via a first portion of the light-guide cable only by the activation of the hand transmitter inserted into the receptacle and thereupon radiates, via a second portion of the light-guide cable towards the outer termination thereof, a signal differing from the control signals of the hand transmitter. Here, therefore, in contrast to the two designs described above, it is necessary to have at least one additional transmitter, which, however, works solely in dependence on the activation of the hand transmitter. These technical safety precautions make sure that the external access control device cannot be controlled directly by the hand transmitter outside the vehicle.
In another known remote-control system (German Patent Document DE 3,043,627 C2) with a movable infrared hand transmitter which can be used outside a vehicle for the remote control of the vehicle locking or of an electrical garage-door drive, there are no technical safety precautions against the simultaneous reception of the hand-transmitter signal by the vehicle receiver and the garage-door receiver.
There is also known a remote-control system (U.S. Pat. No. 2,543,789) which allows the control of the garage-door drive via two receivers external to the vehicle and two corresponding transmitters arranged fixed in a vehicle. The latter are jointly activatable from the passenger space by means of a switch for signal generation and transmission. Here, as a technical safety precaution, there is an AND conjunction between the two transmitter signals according to the receivers, but this merely ensures that the garage-door drive responds only when the two transmitter signals are received simultaneously. A remote control of a vehicle-locking function and a transmitter arrangement releasable from the vehicle are not disclosed in U.S. Pat. No. 2,543,789. Any safety precautions of the type mentioned earlier are therefore also superfluous.
Another remote-control system which provides solely for operating a central vehicle locking and belongs to a theft-prevention device for motor vehicles is described in German Patent Document DE 3,240,945 A1. In this system, to protect the vehicle against unauthorized re-use of a code signal transmitted contactlessly from a hand transmitter to the vehicle and inadmissibly recorded, there is installed in or on the vehicle a transmitter which can be activated by the hand transmitter via the receiver fixed to the vehicle. After the transmitter is activated, it emits an all-round interference signal which is intended to be superposed on the hand-transmitter code signal everywhere except at the location of the receiver itself fixed to the vehicle and which, because of its similarity, cannot immediately be separated from this code signal. Apart from the protective effect of the interference signal, no effective use of the transmitter fixed to the vehicle, for example for control purposes, is disclosed. Also, except by activation by the hand transmitter, it cannot be activated at random by the user.
There is also known a central locking system (German Patent Document DE 3,830,511 C1) the electronic control of which gives the user the possibility of unlocking only the driver's door closure individually by actuating its closing point once in the unlocking direction, or of unlocking all the closures of the vehicle centrally by actuating the same closing point twice in quick succession in the unlocking direction.
An object of the invention is to provide a remote-control system of the relevant generic type, already containing technical safety precautions against possible operating errors or undesired simultaneous activation of the vehicle locking and access control device, in such a way that the hand transmitter can nevertheless also be used for the direct control of the access control device.
This and other objects ar achieved by the present invention which provides a remote-control system for closures with a portable hand held transmitter which generates and radiates directed coded control signals upon actuation on the transmission key of the hand held transmitter. At least one first receiver unit is tuned to receive the control signals radiated from the hand transmitter and is arranged on a motor vehicle triggers switching effects on a remotely controllable vehicle locking device after the received control signals have been identified as acceptable. At least one second receiver unit is tuned to receive control signals radiated as a result of the actuation of the transmission key of the hand transmitter for remotely controlling a remotely controllable access control device external to the motor vehicle. This second receiver unit is arranged outside the motor vehicle and triggers switching effects on the access control device after the received control signals have been identified as acceptable. An electrical circuit is provided for preventing at least the triggering of switching effects by the second receiver unit when the control signal radiated as a result of a single actuation of the transmission key of the hand transmitter is received simultaneously by the first and the second receiver unit, by causing to arrive at the second receiver unit only a control signal which significantly differs from the control signal radiated as a result of the actuation of the transmission key of the hand transmitter for remotely controlling the access control device. At least one transmitter is fixed to the motor vehicle, this transmitter being randomly electrically activatable from a passenger space of the motor vehicle independently of the hand transmitter. The transmitter is arranged on the outside of the motor vehicle for direct radiation to the outside of control signals coded in accordance with the control signals radiated by the hand transmitter.
The vehicle acquires at least one outer transmitter which can be activated electrically from the vehicle interior and independently of the hand transmitter. Moreover, filed in the vehicle is at least one code which corresponds to that filed in the hand transmitter and which serves for coding the signal radiated from the outer transmitter, so that this can radiate directly outwards, especially to the second stationary receiver unit of the access control device, at least control signals coded in accordance with the control signals of the hand transmitter. Because the signals which can be radiated from the hand transmitter for the purpose of the remote control of the access control device differ significantly, as a result of technical safety precautions, from those which can be radiated for the purpose of the remote control of the vehicle locking, the remote control of the access control device both directly by the hand transmitter and from the vehicle independently of the hand transmitter is therefore possible without any loss of safety.
According to advantageous developments of the system according to the invention, the technical safety precautions preventing the drive of the access control device external to the vehicle from responding in the event of a remote control of the vehicle locking can preferably be that a single activation of the hand transmitter by means of its only transmission key is sufficient for the remote control of the vehicle locking, whereas said hand transmitter has to be activated more than once, especially twice in quick succession, for the remote control of the access control device, a single control signal of the hand transmitter not being identified as suitable by the receiver unit of the access control device, and in a further improvement the same code signal being generated automatically more than once, especially twice in succession, by the activation of the at least one vehicle transmitter, or that, although a single activation of the hand transmitter is sufficient for the remote control of both the vehicle locking and the access control device, nevertheless when the hand-transmitter control signal is received at the first receiver unit an (interference or blocking) signal different from this is radiated via the at least one outer transmitter of the vehicle, is superposed on the hand-transmitter control signal outside the vehicle, and consequently prevents it from being identified as suitable by the second receiver unit.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.